核酸修饰与表观遗传学的review.pdf

COCHBI-985; NO. OF PAGES 9 Available online at Nucleic acid modifications with epigenetic significance Ye Fu and Chuan He Epigenetic modifications influence gene expression without 5-hydroxymethylcytosine (5hmC), 5-formylcytosine alterations to the underlying nucleic acid sequence. In addition (5fC), and 5-carboxycytosine (5caC) open a new para- to the well-known 5-methylcytosine (5mC), 5- digm of active DNA demethylation through 5mC oxi- hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- dation (Figure 1) [5,6,7 ,8 ,9 ]. Other than serving as carboxycytosine (5caC) have recently been discovered in potential demethylation intermediates, the abundance genomic DNA, which all result from iterative oxidation of 5mC of these versatile modifications is also regulated, and by the TET (Ten-Eleven-Translocate) family of enzymes. Recent these modifications can potentially sculpt the epige- studies have proposed the roles of these oxidized cytosines in netic landscape of a cell by affecting gene expression. mediating active demethylation of 5mC. Through affinity-based In contrast to well-recognized DNA and histone modi- genome-wide sequencing and oxidation-assisted base- fications, the epigenetic function of RNA modifications resolution sequencing methods, 5hmC is found to be has just begun to emerge. Our effort in searching for dynamically regulated during development, and is enriched reversible RNA modifications led to the discovery that mainly in distal regulatory elements in human and mouse 6 6